Compositions and composites of cellulosic and lignocellulosic materials and resins, and methods of making the same

ABSTRACT

Cellulosic or lignocellulosic materials, and compositions and composites made therefrom, are disclosed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of pending U.S. Ser. No. 12/040,275,which is a divisional (and claims the benefit of priority under 35U.S.C. § 120) of pending U.S. Ser. No. 10/994,846, filed Nov. 22, 2004,which is a divisional of U.S. application Ser. No. 10/336,972, filedJan. 6, 2003 which is a continuation-in-part of U.S. patent applicationSer. No. 10/104,414, filed Mar. 21, 2002, which is (1) acontinuation-in-part of U.S. patent application Ser. No. 09/772,593,filed Jan. 30, 2001, which is: (a) a continuation-in-part of U.S. patentapplication Ser. No. 09/337,580, filed Jun. 22, 1999, now issued as U.S.Pat. No. 6,207,729, which is a continuation in part of U.S. patentapplication Ser. No. 08/961,863, filed Oct. 31, 1997, now issued as U.S.Pat. No. 5,973,035, (b) a continuation-in-part of U.S. patentapplication Ser. No. 09/338,209, filed Jun. 22, 1999, which is acontinuation-in-part of U.S. patent application Ser. No. 08/921,807,filed Sep. 2, 1997, now issued as U.S. Pat. No. 5,952,105, and (c) acontinuation in part of U.S. patent application Ser. No. 09/290,031,filed Apr. 9, 1999, now issued as U.S. Pat. No. 6,258,876, which is adivision of U.S. patent application Ser. No. 08/961,863, filed Oct. 31,1997, now issued as U.S. Pat. No. 5,973,035; and (2) acontinuation-in-part of U.S. patent application Ser. No. 09/593,627,filed Jun. 13, 2000, now issued as U.S. Pat. No. 6,448,307, which is acontinuation-in-part of U.S. patent application Ser. Nos. 09/337,580 and09/338,209. All of the above applications and patents are incorporatedby reference in their entireties.

BACKGROUND OF THE INVENTION

The invention relates to texturized cellulosic or lignocellulosicmaterials and compositions and composites made from such texturizedmaterials.

Cellulosic and lignocellulosic materials are produced, processed, andused in large quantities in a number of applications. Once used, thesematerials are usually discarded. As a result, there is anever-increasing amount of waste cellulosic and lignocellulosic material.

SUMMARY OF THE INVENTION

In general, the invention features texturized cellulosic orlignocellulosic materials and compositions and composites madetherefrom.

In one embodiment, the features a process for manufacturing a composite.The method includes the steps of (a) shearing cellulosic orlignocellulosic fiber to the extent that its internal fibers aresubstantially exposed to form texturized cellulosic or lignocellulosicfiber, and (b) combining the cellulosic or lignocellulosic fiber with aresin. These steps can be carried out in any order (i.e., (a) then (b),or (b) then (a)) or concurrently (i.e., at around the same time). Theresin can be, for example, a thermoplastic resin, a thermosetting resin,an elastomer, a tar, an asphalt, or a lignin. Specific examples includepolystyrene, polycarbonate, polybutylene, thermoplastic polyester,polyether, thermoplastic polyurethane, PVC, Nylon, alkyd, diallylphthalate, epoxy, melamine, phenolic, silicone, urea, thermosettingpolyester, natural rubber, isoprene rubber, styrene-butadienecopolymers, neoprene, nitrile rubber, butyl rubber, ethylene propylenecopolymer (i.e., “EPM”), ethylene propylene diene terpolymer (i.e.,“EPDM”), hypalon, acrylic rubber, polysulfide rubber, silicones,urethanes, fluoroelastomers, butadiene, or epichlorohydrin rubber.

The fiber can be, for example, jute, kenaf, flax, hemp, cotton, rag,paper, paper products, or byproducts of paper manufacturing. Specificexamples include pulp board, newsprint, magazine paper, poly-coatedpaper, and bleached kraft board. The fiber can be a natural or syntheticcelluosic or lignocellulosic material, and can be woven or non-wovenmaterial.

The shearing step can be carried out using a rotary cutter or othermechanical method prior to combining with resin, or can be carried outin situ in a compounding machine or extruder. In some cases, a screw inthe compounding machine or extruder can be effective for shearing thematerial.

In certain embodiments, the method can also include, after step (a) butprior to step (b), densifying the texturized fiber. The densificationstep increases the bulk density of the texturized material, generally bya factor of at least two or three. In some cases, the bulk density canbe increased by a factor of five to ten or more. A preferred range ofbulk densities for the densified texturized fiber is about 5-25 poundsper cubic foot. A more preferred range is about 8-15 pounds per cubicfoot. The densification step can result in the compression of thetexturized fiber into pellets of any shape or size.

The composite manufactured by the above methods is also an aspect of theinvention. In a typical composite of the invention, at least about 50%of the fibers have a length/diameter ratio of at least about 5 (e.g., 5,10, 15, 25, 30, 35, 40, 50, or more)

A composition that includes such composites, together with a chemical orchemical formulation, is also an aspect of the invention. Examples ofsuch chemical formulations include compatibilizers such as FUSABOND®that allow for blending, bonding, adhesion, interphasing, and/orinterfacing between otherwise incompatible materials such as hydrophilicfibers and hydrophobic resins.

In another embodiment, the invention features a process for preparing atexturized fibrous material. The process involves shearing a cellulosicor lignocellulosic material having internal fibers (e.g., flax; hemp;cotton; jute; rags; finished or unfinished paper, paper products,including poly-coated paper, or byproducts of paper manufacturing suchas pulp board; or synthetic cellulosic or lignocellulosic materials suchas rayon), to the extent that the internal fibers are substantiallyexposed, resulting in texturized fibrous material. The cellulosic orlignocellulosic material can be a woven material such as a woven fabric,or a non-woven material such as paper or bathroom tissue. The exposedfibers of the texturized fibrous material can have a length/diameter(L/D) ratio of at least about 5 (at least about 5, 10, 25, 50, or more).For example, at least about 50% of the fibers can have L/D ratios ofthis magnitude.

In another embodiment, the invention features a texturized fibrousmaterial that includes a cellulosic or lignocellulosic material havinginternal fibers, where the cellulosic or lignocellulosic material issheared to the extent that the internal fibers are substantiallyexposed.

The texturized fibrous material can, for example, be incorporated into(e.g., associated with, blended with, adjacent to, surrounded by, orwithin) a structure or carrier (e.g., a netting, a membrane, a flotationdevice, a bag, a shell, or a biodegradable substance). Optionally, thestructure or carrier may itself be made from a texturized fibrousmaterial (e.g., a texturized fibrous material of the invention), or of acomposition or composite of a texturized fibrous material.

The texturized fibrous material can have a bulk density less than about0.5 grams per cubic centimeter, or even less than about 0.2 g/cm³.

Compositions that include the texturized fibrous materials describedabove, together with a chemical or chemical formulation (e.g., apharmaceutical such as an antibiotic or contraceptive, optionally withan excipient; an agricultural compound such as a fertilizer, herbicide,or pesticide; or a formulation that includes enzymes) are also withinthe scope of the invention, as are compositions that include thetexturized fibrous materials and other liquid or solid ingredients(e.g., particulate, powdered, or granulated solids such as plant seed,foodstuffs, or bacteria).

Composites that include thermoplastic resin and the texturized fibrousmaterials are also contemplated. The resin can be, for example,polyethylene, polypropylene, polystyrene, polycarbonate, polybutylene, athermoplastic polyester, a polyether, a thermoplastic polyurethane,polyvinylchloride, or a polyamide, or a combination of two or moreresins.

In some cases, at least about 5% by weight (e.g., 5%, 10%, 25%, 50%,75%, 90%, 95%, 99%, or about 100%) of the fibrous material included inthe composites is texturized.

The composite may include, for example, about 30% to about 70% by weightresin and about 30% to about 70% by weight texturized fibrous material,although proportions outside of these ranges may also be used. Thecomposites can be quite strong, in some cases having a flexural strengthof at least about 6,000 to 10,000 psi.

In another embodiment, the invention features a composite including aresin, such as a thermoplastic resin, and at least about 2% by weight,more preferably at least about 5% by weight, texturized cellulosic orlignocellulosic fiber. The invention also features a composite thatincludes polyethylene and at least about 50% by weight texturizedcellulosic or lignocellulosic fiber.

The invention further features composites, including a resin andcellulosic or lignocellulosic fiber, that have flexural strengths of atleast about 3,000 psi, or tensile strengths of at least about 3,000 psi.

In addition, the invention features a process for manufacturing acomposite; the process includes shearing cellulosic or lignocellulosicfiber to form texturized cellulosic or lignocellulosic fiber, thencombining the texturized fiber with a resin. A preferred method includesshearing the fiber with a rotary knife cutter. The invention alsofeatures a process for manufacturing a composite that includes shearingcellulosic or lignocellulosic fiber and combining the fiber with aresin.

The composites described above can also include inorganic additives suchas calcium carbonate, graphite, asbestos, wollastonite, mica, glass,fiber glass, chalk, talc, silica, ceramic, ground construction waste,tire rubber powder, carbon fibers, or metal fibers (e.g., stainlesssteel or aluminum). Such inorganic additives can represent, for example,about 0.5% to about 20% of the total weight of the composite.

The composites can be in the form of, for example, a pallet (e.g., aninjection molded pallet), pipes, panels, decking materials, boards,housings, sheets, poles, straps, fencing, members, doors, shutters,awnings, shades, signs, frames, window casings, backboards, wallboards,flooring, tiles, railroad ties, forms, trays, tool handles, stalls,bedding, dispensers, staves, films, wraps, totes, barrels, boxes,packing materials, baskets, straps, slips, racks, casings, binders,dividers, walls, indoor and outdoor carpets, rugs, wovens, and mats,frames, bookcases, sculptures, chairs, tables, desks, art, toys, games,wharves, piers, boats, masts, pollution control products, septic tanks,automotive panels, substrates, computer housings, above- andbelow-ground electrical casings, furniture, picnic tables, tents,playgrounds, benches, shelters, sporting goods, beds, bedpans, thread,filament, cloth, plaques, trays, hangers, servers, pools, insulation,caskets, book covers, clothes, canes, crutches, and other construction,agricultural, material handling, transportation, automotive, industrial,environmental, naval, electrical, electronic, recreational, medical,textile, and consumer products. The composites can also be in the formof a fiber, filament, or film.

The terms “texturized cellulosic or lignocellulosic material” and“texturized fibrous material” as used herein, mean that the cellulosicor lignocellulosic material has been sheared to the extent that itsinternal fibers are substantially exposed. At least about 50%, morepreferably at least about 70%, of these fibers have a length/diameter(L/D) ratio of at least 5, more preferably at least 25, or at least 50.An example of texturized cellulosic material is shown in FIG. 1.

The texturized fibrous materials of the invention have properties thatrender them useful for various applications. For example, the texturizedfibrous materials have absorbent properties, which can be exploited, forexample, for pollution control. The fibers are generally biodegradable,making them suitable, for example, for drug or chemical delivery (e.g.,in the treatment of humans, animals, or in agricultural applications).The texturized fibrous materials can also be used to reinforce polymericresins.

The term “thermosetting resin”, as used herein, refers to plastics(e.g., organic polymers) that are cured, set, or hardened into apermanent shape. Curing is an irreversible chemical reaction typicallyinvolving molecular cross-linking using heat or irradiation (e.g., UVirradiation). Curing of thermosetting materials can be initiated orcompleted at, for example, ambient or higher temperatures. Thecross-linking that occurs in the curing reaction is brought about by thelinking of atoms between or across two linear polymers, resulting in athree-dimensional rigidified chemical structure.

Examples of thermosetting resins include, but are not limited to,silicones, alkyds, diallyl phthalates (allyls), epoxies, melamines,phenolics, certain polyesters, silicones, ureas, polyurethanes,polyolefin-based thermosetting resins such as TELENE™ (BF Goodrich) andMETTON™ (Hercules).

The term “elastomer”, as used herein, refers to macromolecular materialsthat rapidly return to approximate their initial dimensions and shapeafter deformation and subsequent release.

Examples of elastomers include, but are not limited to, natural rubber,isoprene rubber, styrene-butadiene copolymers, neoprene, nitrile rubber,butyl rubber, ethylene propylene copolymer (i.e., “EPM”) and ethylenepropylene diene terpolymer (i.e., “EPDM”), hypalon, acrylic rubber,polysulfide rubber, silicones, urethanes, fluoroelastomers, butadiene,and epichlorohydrin rubber.

The term “tar”, as used herein, means a typically thick brown to blackliquid mixture of hydrocarbons and their derivatives obtained bydistilling wood, peat, coal, shale, or other vegetable or mineralmaterials. An example is coal tar, which is made by destructivedistillation of bituminous coal or crude petroleum (e.g., containingnaphthalene, toluene, quinoline, aniline, and cresols).

The term “lignin”, as used herein, refers to an amorphous substance,mixture, or powder isolated from wood, plants, recycled wood or plantproducts, or as a byproduct of papermaking. In nature, lignins, togetherwith cellulose, form the woody cell walls of plants and the cementingmaterial between them. They are typically polymeric and may bedistinguished from cellulose by (1) a higher carbon content thancellulose, and (2) the inclusion of propyl-benzene units, methoxylgroups, and/or hydroxyl groups. They are generally not hydrolyzed byacids but may be soluble in hot alkali and bisulfite, and may be readilyoxidizable. Lignins can be recovered from the liquor that results fromthe sulfate or soda process of making cellulosic pulp, or from sulfiteliquor. The term lignin thus includes sulfite lignin, orlignin-sulfonates.

The term “asphalt”, as used herein, refers, for example, to anamorphous, solid, or semisolid mixture of hydrocarbons, brownish-blackpitch, or bitumen, produced from the higher-boiling point minerals oilsby the action of oxygen. Asphalts include both asphaltenes and carbenes.Asphalts are commonly used for paving, roofing, and waterproofingmaterials.

The new compositions have properties that render them useful for variousapplications. Compositions that include texturized fibrous material andmatrices are, for example, strong, lightweight, and inexpensive.

Other advantages afforded by the texturized fibers include:

(1) Reduced densities of matrix materials such as elastomers andthermosetting resins.

(2) Higher impact resistance due to increased interfacial area betweenmatrix and texturized fiber and increased energy absorbed whentexturized fiber delaminates from matrices.

(3) Reduced surface friction.

(4) Higher lubricity surfaces.

(5) Enhanced tolerance for and compatibilization of both the hydrophobicand hydrophilic constituents in the matrices.

(6) Enhanced ability to custom tailor the properties of the compositionfor specific requirements.

The raw materials used to make the composites are available as virgin orrecycled materials; for example, they may include discarded containerscomposed of resins, and waste cellulosic or lignocellulosic fiber.

Other features and advantages of the invention will be apparent from thefollowing detailed description, and from the claims.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a photograph of a texturized newspaper, magnified fifty times;

FIG. 2 is a photograph of texturized poly-coated paper, magnified fiftytimes;

FIG. 3 is a photograph of a half-gallon polyboard juice carton;

FIG. 4 is a photograph of shredded half-gallon polyboard juice cartons;and

FIG. 5 is a photograph of texturized fibrous material prepared byshearing the shredded half-gallon polyboard juice cartons of FIG. 4.

DETAILED DESCRIPTION OF THE INVENTION

Examples of cellulosic raw materials include paper and paper productssuch as newsprint, poly-coated paper, and effluent from papermanufacture; examples of lignocellulosic raw materials include wood,wood fibers, and wood-related materials, as well as materials derivedfrom kenaf, grasses, rice hulls, bagasse, cotton, jute, other stemplants (e.g., hemp, flax, bamboo; both bast and core fibers), leafplants (e.g., sisal, abaca), and agricultural fibers (e.g., cerealstraw, corn cobs, rice hulls, and coconut hair). Aside from virgin rawmaterials, post-consumer, industrial (e.g., offal), and processing waste(e.g., effluent) can also be used as fiber sources.

Preparation of Texturized Fibrous Material

If scrap cellulosic or lignocellulosic materials are used, they shouldpreferably be clean and dry, although the materials can alternatively besheared after wetting, either with water, a solvent, a compatibilizer,or a resin. The raw material can be texturized using any one of a numberof mechanical means, or combinations thereof. One method of texturizingincludes first cutting the cellulosic or lignocellulosic material into¼- to ½-inch pieces, if necessary, using a standard cutting apparatus.Counter-rotating screw shredders and segmented rotating screw shredderssuch as those manufactured by Munson (Utica, N.Y.) can also be used, ascan a standard document shredder as found in many offices.

The cellulosic or lignocellulosic material can then be sheared with arotary cutter, such as the one manufactured by Sprout, WaldronCompanies, as described in Perry's Chem. Eng. Handbook, 6th Ed., at 8-29(1984). Although other settings can be used, the spacing between therotating knives and bed knives of the rotary cutter is typically set to0.020″ or less, and blade rotation is set to 750 rpm or more. The rotarycutter can be cooled to 100° C. or lower during the process, forexample, using a water jacket.

The texturized material is passed through a discharge screen. Largerscreens (e.g., up to 6 mm) can be used in large-scale production. Thecellulosic or lignocellulosic feedstock is generally kept in contactwith the blades of the rotary cutter until the fibers are pulled apart;smaller screens (e.g., 2 mm mesh) provide longer residence times andmore complete texturization, but can result in lower length/diameter(L/D) aspect ratios. A vacuum drawer can be attached to the screen tomaximize and maintain fiber length/diameter aspect ratio.

The texturized fibrous materials can be directly stored in sealed bagsor may be dried at approximately 105° C. for 4-18 hours (e.g., until themoisture content is less than about 0.5%) immediately before use. FIG. 1is an SEM photograph of texturized newspaper.

Alternative texturizing methods include stone grinding, mechanicalripping or tearing, and other methods whereby the material's internalfibers can be exposed (e.g., pin grinding, air attrition milling).Examples of such other methods can also include in situ shearing in acompounding machine used to mix the fibers with resin or in an extruder.The fibrous material can be, for example, added before, after, orconcurrent with the addition of the resin, irrespective of whether theresin is in a solid form (e.g., powdered or pelletized) form or a liquidform (e.g., molten or in solution).

After the material has been texturized, it can optionally be“densified,” or compacted, to facilitate transport, storage, handling,processing, and/or feeding into compounding or extruding equipment.Densification can be carried out using a roll mill (which can formpellets or other shapes), for example, or a pellet mill. Pelletizingmachines used in agriculture, pharmaceuticals (e.g., “pilling”machines), metallurgy, and other industries can be used or adapted foruse for densifying texturized fiber.

During densification, the bulk density of the texturized material isincreased. For example, whereas virgin poly-coated paper might have abulk density of about 13 pounds per cubic foot, and texturizedpoly-coated paper might have a bulk density of about 2-6 pounds percubic foot (i.e., about 0.03-0.1 g/cc), the densified material derivedtherefrom can have a bulk density as high as 25 pounds per cubic footusing a pellet mill. Preferably, the bulk density of the densified fiberdoes not exceed the bulk density of the starting material. Thus, in thecase of poly-coated paper having a bulk density of 13 pounds per cubicfoot, the preferred bulk density for the densified texturized fiber willbe in the vicinity of 10-12 pounds per cubic foot. A bulk density inthis range can allow for a relatively high feed rate in an extrusionprocess (i.e., about 10 times greater than that of a material having abulk density of 2.8) without destroying the integrity of the texturizedfiber. The densified texturized fiber can be substituted fornon-densified texturized fiber in many applications, because, eventhough the densified texturized fiber has a relatively high bulkdensity, once the densified fiber is fed into compounding, extrusion, orother processing devices, the fibers can readily re-“open” to re-exposethe fibers.

Uses of Texturized Fibrous Material

Texturized fibrous materials and compositions and composites of suchfibers with other chemicals and chemical formulations can be prepared totake advantage of the materials' properties. The materials can be usedto absorb chemicals, for example, potentially absorbing many times theirown weight. Thus, the materials could, for instance, be used to absorbspilled oil, or for clean up of environmental pollution, for example, inwater, in the air, or on land. Similarly, the material's absorbentproperties, together with its biodegradability, also make them usefulfor delivery of chemicals or chemical formulations. For example, thematerials can be treated with solutions of enzymes or pharmaceuticalssuch as antibiotics, nutrients, or contraceptives, and any necessaryexcipients, for drug delivery (e.g., for treatment of humans or animals,or for use as or in animal feed and/or bedding), as well as withsolutions of fertilizers, herbicides, or pesticides. The materials canoptionally be chemically treated to enhance a specific absorptionproperty. For example, the materials can be treated with silanes torender them lipophilic.

Compositions including texturized materials combined with liquids orparticulate, powdered, or granulated solids can also be prepared. Forexample, texturized materials can be blended with seeds (i.e., with orwithout treatment with a solution of fertilizer, pesticides, etc.),foodstuffs, or bacteria (e.g., bacteria that digest toxins). The ratioof fibrous materials to the other components of the compositions willdepend on the nature of the components and readily be adjusted for aspecific product application.

In some cases, it may be advantageous to associate the texturizedfibrous materials, or compositions or composites of such materials, witha structure or carrier such as a netting, a membrane, a flotationdevice, a bag, a shell, or a biodegradable substance. Optionally, thestructure of carrier may itself be made of a texturized fibrous material(e.g., a material of the invention), or a composition or compositethereof.

Composites of Texturized Fibrous Material and Resin

Texturized fibrous materials can also be combined with resins to formstrong, lightweight composites. Materials that have been treated withchemicals or chemical formulations, as described above, can similarly becombined with biodegradable or non-biodegradable resins to formcomposites, allowing the introduction of, for example, hydrophilicsubstances into otherwise hydrophobic polymer matrices. Alternatively,the composites including texturized fibrous materials and resin can betreated with chemicals or chemical formulations.

The texturized cellulosic or lignocellulosic material provides thecomposite with strength. The composite may include from about 10% toabout 90%, for example from about 30% to about 70%, of the texturizedcellulosic or lignocellulosic material by weight.

The resin encapsulates the texturized cellulosic or lignocellulosicmaterial in the composites, and helps control the shape of thecomposites. The resin also transfers external loads to the fibrousmaterials and protects the fiber from environmental and structuraldamage. Composites can include, for example, about 10% to about 90%,more preferably about 30% to about 70%, by weight, of the resin.

Resins are used in a variety of applications, for example, in foodpackaging. Food containers made of resins are typically used once, andthen discarded. Examples of resins that are suitably combined withtexturized fibers include polyethylene (including, e.g., low densitypolyethylene and high density polyethylene), polypropylene, polystyrene,polycarbonate, polybutylene, thermoplastic polyesters (e.g., PET),polyethers, thermoplastic polyurethane, PVC, polyamides (e.g., nylon)and other resins. It is preferred that the resins have a low melt flowindex. Preferred resins include polyethylene and polypropylene with meltflow indices of less than 3 g/10 min, and more preferably less than 1g/10 min.

The resins can be purchased as virgin material, or obtained as wastematerials, and can be purchased in pelletized or granulated form. Onesource of waste resin is used polyethylene milk bottles. If surfacemoisture is present on the pelletized or granulated resin, however, itshould be dried before use.

The composites can also include coupling agents. The coupling agentshelp to bond the hydrophilic fibers to the hydrophobic resins. Examplesof coupling agents include maleic anhydride modified polyethylenes, suchthose in the FUSABOND® (available from Dupont, Delaware) and POLYBOND®(available from Uniroyal Chemical, Connecticut) series. One suitablecoupling agent is a maleic anhydride modified high-density polyethylenesuch as FUSABOND® MB 100D.

The composites can also contain additives known to those in the art ofcompounding, such as plasticizers, lubricants, antioxidants, opacifiers,heat stabilizers, colorants, flame-retardants, biocides, impactmodifiers, photostabilizers, and antistatic agents.

The composites can also include inorganic additives such as calciumcarbonate, graphite, asbestos, wollastonite, mica, glass, fiber glass,chalk, silica, talc, ceramic, ground construction waste, tire rubberpowder, carbon fibers, or metal fibers (e.g., aluminum, stainlesssteel). When such additives are included, they are typically present inquantities of from about 0.5% up to about 20-30% by weight. For example,submicron calcium carbonate can be added to the composites of fiber andresin to improve impact modification characteristics or to enhancecomposite strength.

Preparation of Compositions

Compositions containing the texturized cellulosic or lignocellulosicmaterials and chemicals, chemical formulations, or other solids can beprepared, for example, in various immersion, spraying, or blendingapparatuses, including, but not limited to, ribbon blenders, coneblenders, double cone blenders, and Patterson-Kelly “V” blenders.

For example, a composition containing 90% by weight texturizedcellulosic or lignocellulosic material and 10% by weight ammoniumphosphate or sodium bicarbonate can be prepared in a cone blender tocreate a fire-retardant material for absorbing oil.

Preparation of Composites of Texturized Fiber and Resin

Composites of texturized fibrous material and resin can be prepared asfollows. A standard rubber/plastic compounding 2-roll mill is heated to325-400° F. The resin (usually in the form of pellets or granules) isadded to the heated roll mill. After about 5 to 10 minutes, the couplingagent is added to the roll mill. After another five minutes, thetexturized cellulosic or lignocellulosic material is added to the moltenresin/coupling agent mixture. The texturized material is added over aperiod of about 10 minutes.

The composite is removed from the roll mill, cut into sheets and allowedto cool to room temperature. It is then compression molded into plaquesusing standard compression molding techniques.

Alternatively, a mixer, such as a Banbury internal mixer, is chargedwith the ingredients. The ingredients are mixed, while the temperatureis preferably maintained at less than about 190° C. The mixture can thenbe compression molded.

In another embodiment, the ingredients can be mixed in an extrudermixer, such as a twin-screw extruder equipped with co-rotating screws.The resin and the coupling agent are introduced at the extruder feedthroat; the texturized cellulosic or lignocellulosic material isintroduced about ⅓ of the way down the length of the extruder into themolten resin. The internal temperature of the extruder is preferablymaintained at less than about 190° C., although higher temperatures(e.g., 270° C.) might be encountered during extrusion of certainprofiles. At the output, the composite can be, for example, pelletizedby cold strand cutting.

Alternatively, the mixture can first be prepared in a mixer, thentransferred to an extruder.

In another embodiment, the composite can be formed into fibers, usingfiber-forming techniques known to those in the art, or into filamentsfor knitting, warping, weaving, braiding, or making non-wovens. In afurther embodiment, the composite can be made into a film.

Properties of the Composites of Texturized Fibrous Material and Resin

The resulting composites include a network of fibers, encapsulatedwithin a resin matrix. The fibers form a lattice network, which providesthe composite with strength. Since the cellulosic or lignocellulosicmaterial is texturized, the amount of surface area available to bond tothe resin is increased, in comparison to composites prepared withun-texturized cellulosic or lignocellulosic material. The resin binds tothe surfaces of the exposed fibers, creating an intimate blend of thefiber network and the resin matrix. The intimate blending of the fibersand the resin matrix further strengthens the composites.

These compositions can also include inorganic additives such as calciumcarbonate, graphite, asbestos, wollastonite, mica, glass, fiber glass,chalk, silica, talc, flame retardants such as alumina trihydrate ormagnesium hydroxide, ground construction waste, tire rubber powder,carbon fibers, or metal fibers (e.g., aluminum, stainless steel). Theseadditives may reinforce, extend, change electrical or mechanical orcompatibility properties, and may provide other benefits. When suchadditives are included, they may be present in loadings by weight frombelow 1% to as high as 80%. Typical loadings ranges are between 0.5% and50% by weight.

Polymeric and elastomeric compositions can also include coupling agents.The coupling agents help to bond the hydrophilic fibers of thetexturized fibrous material to the resins.

The compositions having thermosetting or elastomer matrices can alsocontain additives known to those in the art of compounding, such asplasticizers; lubricants; antioxidants; opacifiers; heat stabilizers;colorants; impact modifiers; photostabilizers; biocides; antistaticagents; organic or inorganic flame retardants, biodegradation agents;and dispersants. Special fiber surface treatments and additives can beused when a specific formulation requires specific property improvement.

The following are non-limiting examples of compositions:

Thermosetting Resins Compositions of texturized fibrous material andthermosetting resins can be prepared as bulk molding compounds (BMCs),sheet molding compounds (SMCs), or as other formulations.

Bulk molding compounds (BMCs) are materials made by combining a resinand chopped fibers in a dough mixer, then mixing until the fibers arewell wetted and the material has the consistency of modeling clay. MostBMCs are based on polyesters, but vinyl esters and epoxies are sometimesused. A pre-weighed amount of the compound is placed in a compressionmold, which is then closed and heated under pressure to cross-link thethermosetting polymer. Many electrical parts are made using BMCcompounds and processing. Other applications include microwave dishes,tabletops, and electrical insulator boxes.

Sheet molding compounds (SMCs) are made by compounding a polyester resinwith fillers, pigments, catalysts, mold release agents, and/or specialthickeners that react with the polymer to greatly increase theviscosity. The resin mixture is spread onto a moving nylon film. Theresin passes under feeders, which disperse the texturized fibers. Asecond film is placed on top, sandwiching the compound inside. Thematerial then passes through rollers that help the resin to wet thefibers, and the material is rolled up. Prior to use, the nylon films areremoved and the compound is molded.

Other techniques and preparation procedures can be used to prepare andcure thermosetting systems.

Elastomers: Compositions of texturized fibrous material and elastomerscan be prepared by known methods. In one method, for example, theelastomer is added to a rubber/plastic compounding two-roll mill. Aftera couple of minutes, the other ingredients, including a vulcanizingagent, are added to the roll mill. Once the elastomer has beencompounded, the texturized fibrous material is added to the roll mill.The texturized fibrous material is added over a period of about 10minutes. The compounded material is removed from the roll mill and cutinto sheets. It is then compression molded into the desired shape usingstandard compression molding techniques.

Alternatively, a mixer, such as a Banbury internal mixer or appropriatetwin or single screw compounder can be used. If a Banbury mixer is used,the compounded mixture can, for example, be discharged and dropped ontoa roll mill for sheeting. Single or twin-screw compounders produce asheet as an extrudate. The mixture can then be compression molded.Likewise, single- or twin-screw compounders can extrude a shaped profilethat can be directly vulcanized. The composition can be molded,extruded, compressed, cut, or milled.

Uses of the Composites of Texturized Fibrous Material and Resin

The resin/fibrous material composites can be used in a number ofapplications. The composites are strong and light weight; they can beused, for example, as wood substitutes. The resin coating renders thecomposites water-resistant, so they may be used in outdoor applications.For example, the composites may be used to make pallets, which are oftenstored outdoors for extended periods of time, wine staves, rowboats,furniture, skis, and oars. Many other uses are contemplated, includingpanels, pipes, decking materials, boards, housings, sheets, poles,straps, fencing, members, doors, shutters, awnings, shades, signs,frames, window casings, backboards, wallboards, flooring, tiles,railroad ties, forms, trays, tool handles, stalls, bedding, dispensers,staves, films, wraps, totes, barrels, boxes, packing materials, baskets,straps, slips, racks, casings, binders, dividers, walls, indoor andoutdoor carpets, rugs, wovens, and mats, frames, bookcases, sculptures,chairs, tables, desks, art, toys, games, wharves, piers, boats, masts,pollution control products, septic tanks, automotive panels, substrates,computer housings, above- and below-ground electrical casings,furniture, picnic tables, tents, playgrounds, benches, shelters,sporting goods, beds, bedpans, thread, filament, cloth, plaques, trays,hangers, servers, pools, insulation, caskets, book covers, clothes,canes, crutches, and other construction, agricultural, materialhandling, transportation, automotive, industrial, environmental, naval,electrical, electronic, recreational, medical, textile, and consumerproducts. Numerous other applications are also envisioned. Thecomposites may also be used, for example, as the base or carcass for aveneer product, or sandwiched between layers of paper or other material.Moreover, the composites can be, for example, surface treated, grooved,milled, shaped, imprinted, textured, compressed, punched, or colored.

The following examples illustrate certain embodiments and aspects of thepresent invention and not to be construed as limiting the scope thereof.

EXAMPLES Example 1

A 1500-pound skid of virgin, half-gallon juice cartons made ofpoly-coated white kraft board was obtained from International Paper. Onesuch carton is shown in FIG. 3. Each carton was folded flat.

The cartons were fed into a 3 hp Flinch Baugh shredder at a rate ofapproximately 15 to 20 pounds per hour. The shredder was equipped withtwo rotary blades, each 12″ in length, two fixed blades, and a 0.3″discharge screen. The gap between the rotary and fixed blades was 0.10″.

A sample of the output from the shredder, consisting primarily ofconfetti-like pieces, about 0.1″ to 0.5″ in width and about 0.25″ to 1″in length, is shown in FIG. 4. The shredder output was fed into a ThomasWiley Mill Model 2D5 rotary cutter. The rotary cutter had four rotaryblades, four fixed blades, and a 2 mm discharge screen. Each blade wasapproximately 2″ long. The blade gap was set at 0.020″.

The rotary cutter sheared the confetti-like pieces across the knifeedges, tearing the pieces apart and releasing a finely texturized fiberat a rate of about one pound per hour. The fiber had an average minimumL/D ratio of between five and 100 or more. The bulk density of thetexturized fiber was on the order of 0.1 g/cc. A sample of texturizedfiber is shown in FIG. 5 at normal magnification, and in FIG. 2 atfifty-fold magnification.

Example 2

Composites of texturized fiber and resin were prepared as follows. Astandard rubber/plastic compounding 2-roll mill was heated to 325-400°F. The resin (usually in the form of pellets or granules) was added tothe heated roll mill. After about 5 to 10 minutes, the resin banded onthe rolls (i.e., it melted and fused on the rolls). The coupling agentwas then added to the roll mill. After another five minutes, thetexturized cellulosic or lignocellulosic material was added to themolten resin/coupling agent mixture. The cellulosic or lignocellulosicfiber was added over a period of about 10 minutes.

The composite was then removed from the roll mill, cut into sheets, andallowed to cool to room temperature. Batches of about 80 g each werecompression molded into 6″×6″×⅛″ plaques using standard compressionmolding techniques.

One composition contained the following ingredients:

Composition No. 1 Ingredient Amount(g) High density polyethylene¹ 160Old newspaper² 240 Coupling agent³ 8 ¹Marlex 16007 ²Texturized usingrotary cutter with 2 mm mesh ³FUSABOND ® 100D

The plaques were machined into appropriate test specimens and testedaccording to the procedures outlined in the method specified. Threedifferent specimens were tested for each property, and the mean valuefor each test was calculated.

The properties of Composition No. 1 are as follows:

Flexural strength (10³ psi) 9.81 (ASTM D790)

Flexural modulus (10⁵ psi) 6.27 (ASTM D790)

A second composition contains the following ingredients:

Composition No. 2 Ingredient Amount(g) High density polyethylene¹ 160Old magazines² 240 Coupling agent³ 8

The properties of Composition No. 2 are as follows:

Flexural strength (10³ psi) 9.06 (ASTM D790) Flexural modulus (10⁵ psi)6.78 (ASTM D790)

A third composition contains the following ingredients:

Composition No. 3 Ingredient Amount(g) HDPE¹ 160 Fiber paper² 216 3.1 mmtexturized kenaf 24 Coupling agent³ 8

The properties of Composition No. 3 are as follows:

Flexural strength (10³ psi) 11.4 (ASTM D790) Flexural modulus (10⁵ psi)6.41 (ASTM D790)

A fourth composition contains the following ingredients:

Composition No. 4 Ingredient Amount (g) SUPERFLEX ® CaCO₃ 33 Fiber^(2,4)67 HDPE (w/3% compatibilizer)^(1,3) 100 ⁴Virgin poly-coated milk cartons

The properties of Composition No. 4 are as follows:

Flexural strength (10⁵ psi) 8.29 (ASTM D790) Ultimate elongation (%) <5(ASTM D638) Flexural modulus (10⁵ psi) 10.1 (ASTM D790) Notch Izod(ft-lb/in) 1.39 (ASTM D256-97)

A fifth composition contains the following ingredients:

Composition No. 5 Ingredient Amount (parts) SUPERFLEX ® CaCO₃ 22Fiber^(2,4) 67 HDPE (w/3% compatibilizer)^(1,3) 100

The properties of Composition No. 5 are as follows:

Flexural strength (10⁵ psi) 8.38 (ASTM D790) Ultimate elongation (%) <5(ASTM D638) Flexural modulus (10⁵ psi) 9.86 (ASTM D790) Notch Izod(ft-lb/in) 1.37 (ASTM D256-97)

A sixth composition contains the following ingredients:

Composition No. 6 Ingredient Amount (parts) ULTRAFLEX ® CaCO₃ 33Fiber^(2,4) 67 HDPE/compatibilizer^(1,3) 100

The properties of Composition No. 6 are as follows:

Flexural strength (10⁵ psi) 7.43 (ASTM D790) Ultimate elongation (%) <5(ASTM D638) Flexural modulus (10⁵ psi) 11.6 (ASTM D790) Notch Izod(ft-lb/in) 1.27 (ASTM D256-97)

A seventh composition contains the following ingredients:

Composition No. 7 Ingredient Amount (pbw) HDPE (w/3%compatibilizer)^(3,5) 60 Kraftboard² 40 ⁵HDPE with melt-flow index <1

The properties of Composition No. 7 are as follows:

Flexural Strength (10⁵ psi) 7.79 (ASTM D790) Ultimate elongation (%)  <5 (ASTM D638) Flexural Modulus (10⁵ psi) 7.19 (ASTM D790)

Example 3

Foamed epoxies are used in thermal insulation applications wheresuperior water resistance and elevated temperature properties aredesired. Such epoxies can be reinforced with texturized fiber preparedaccording to the procedure in Example 3. Fillers such as calciumcarbonate may optionally be used to obtain some cost reductions.However, overloading with filler can weaken the strength of the foamcell walls, particularly when the foam densities are in the range offive pounds per cubic foot or less, since such low foam density canresult in thin, fragile walls within the foam. Filler loadings aregenerally in the four to five pounds/hundred weight (phr) of resin.Reinforcing with texturized fiber can also provide for reduced weightand cost. In addition, improved strength can be realized because of thehigh length-to-diameter (L/D) ratios of the texturized fiber. It is notunreasonable to employ up to 30 phr of the fiber.

A typical formulation includes:

Ingredient Parts DGEBA (diglycidyl ether, of bisphenol A) 100 MPDA(m-phenylenediamine) 10 Celogen ® (p,p-oxybis-benzenesulfonylhydrazide)10 (Uniroyal Chemical Company) Surfactant 0.15 Styrene Oxide 5Texturized Fiber 30

This formulation is mixed using standard epoxy mixing techniques. Itproduces a very high exotherm at the curing temperature of 120° C. and afoam density of about seven pounds per cubic foot.

Other embodiments are within the claims.

1. A process comprising: re-opening a densified fibrous material, thedensified fibrous material having been prepared by physically treating acellulosic or lignocellulosic material having internal fibers to anextent that the internal fibers have been substantially exposed,providing a material having a bulk density of less than about 0.5 g/cm³,and then densifying the physically treated material.
 2. The process ofclaim 1 wherein re-opening substantially re-exposes the fibers.
 3. Theprocess of claim 1 wherein the densified material has a bulk densitythat does not exceed a bulk density of the cellulosic or lignocellulosicmaterial prior to physical treatment.
 4. The process of claim 1 whereinthe physically treated material has been compressed to density thematerial.
 5. The process of claim 1 wherein the physically treatedmaterial has been sheared.
 6. The process of claim 1 wherein thephysically treated material has been stored in sealed bags.
 7. Theprocess of claim 1 further comprising treating the re-opened fibrousmaterial with an enzyme solution.
 8. The process of claim 1 wherein thecellulosic or lignocellulosic material is selected from the groupconsisting of paper, paper products, wood, wood fibers, kenaf, grasses,rice hulls, bagasse, cotton, jute, flax, hemp, stem plants, leaf plants,and agricultural fibers.
 9. The process of claim 1 further comprisingblending the re-opened fibrous material with a bacteria.
 10. The processof claim 1 wherein the densified material has a bulk density of fromabout 5 to 25 pounds per cubic foot (0.08 to 0.40 g/cm³).
 11. Theprocess of claim 1 wherein the densified material has a bulk density offrom about 8 to 15 pounds per cubic foot (0.13 to 0.24 g/cm³).
 12. Theprocess of claim 1 wherein the densified material has a bulk density offrom about 10 to 12 pounds per cubic foot (0.16 to 0.19 g/cm³).
 13. Theprocess of claim 1 wherein densifying increases bulk density by a factorof at least two.
 14. The process of claim 1 wherein densifying increasesbulk density by a factor of three.
 15. The process of claim 1 whereindensifying has been carried out using a roll mill.
 16. The process ofclaim 1 wherein densifying has been carried out using a pellet mill. 17.The process of claim 1 wherein the densified material is in the form ofpellets.
 18. The process of claim 1 wherein the cellulosic orlignocellulosic material comprises waste paper.